DNA cross-linking by a phototriggered dehydromonocrotaline progenitor

The semisynthesis and DNA cross-linking reactivity of the first photochemically triggered progenitor of dehydromonocrotaline are reported. This masked dehydromonocrotaline represents the first example of a new type of pyrrolizidine alkaloids that are capable of photochemical activation. Data from these studies establish the viability of masked DNA-reactive pyrrolizidine alkaloid progenitors that can be activated photochemically. These progenitors show potential as tools for understanding the mechanism of DNA-DNA and DNA-protein cross-linking.